The determination of whether or not two or more entities make contact with each other during gameplay.

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2answers
646 views

Collision Problems

I'm having some troubles with a 2D platformer type game (there's more to it, but that's all that matters for this question). I had collision with the platforms working fine, but if the character hit ...
31
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3answers
3k views

A ball hits the corner, where will it deflect?

I need to brush up my trigonometry and hope you can help here with a simple mathematical model. Here is my model so far in the image attached. I am aware that the frame animation has other problems ...
3
votes
3answers
340 views

Collision test solution for hack&slash game

I want to ask you what is the best way to deal with collisions in hack&slash game, I know that collisions must be very accurate. My first idea is to use sphere bounds ( I making hack&slash in ...
7
votes
1answer
559 views

XNA 2D Collision Detection without GetData()

I'm currently working on a Worms game which involves terrain deformation. I used to do it with .GetData(), modifying the color array, then using .SetData(), but I looked into changing it to make the ...
5
votes
2answers
1k views

Determining if a character is within the field of view in XNA

I'm trying to creating a field of view for the camera I'm making for a game. It rotates around a circle for 180 degrees while the head moves accordingly. I'm going to bound the field of view within an ...
4
votes
1answer
1k views

Are Loose Octrees Too Loose?

I've been reading Real-Time Collision Detection and for loose octrees it recommends expanding each node's AABB length by a factor of 2, making its expanded volume 8 times as large. I am surprised ...
5
votes
2answers
1k views

Correct order of operations in a platformer game loop

I've run into an issue with my Mega Man engine, and the structure of my game loop is making it very difficult to fix. With Rush Jet, or any falling platform, Mega Man needs to stay attached to the ...
5
votes
3answers
1k views

Android collision detection of a 3d object based on a 2d projection

I am writing a game for android. We have an orthographic view setup, but the characters (ships, projectiles, etc). The enemies / characters will be able to rotate about the x axis. The problem is that ...
13
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1answer
2k views

Quad trees/grid based collision - putting logic into action

First of all, I've only been writing my own game logic for a short while, so I apologize if this might seem straight forward. I've been reading a lot about quad trees and grid based collision ...
2
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4answers
3k views

per pixel based collision detection

I was wondering if anyone had any ideas on how to get per pixel collision detection for the android. I saw that the andEngine has great collision detection on rotation as well but couldn't see where ...
8
votes
4answers
810 views

Moving objects colliding when using unalligned collision avoidance (steering)

I'm having trouble with unaligned collision avoidance for what I think is a rare case. I have set two objects to move towards each other but with a slight offset, so one of the objects is moving ...
3
votes
2answers
1k views

Axis-Aligned Bounding Box- once rotated

Creating an AABB is simple. But, if the 3d model has become rotated, how do you update the AABB to become accurate? Or is the AABB supposed to be in local space?
3
votes
4answers
4k views

Side detection on Rectangle collision detection?

How can I determine which of the sides on a Rectangle that was hit by another Rectangle (or Circle if that's easier)? I originally tried creating 8 subrectangles for my main rectangle - one for each ...
4
votes
1answer
1k views

Points on lines where the two lines are the closest together

I'm trying to find the points on two lines where the two lines are the closest. I've implemented the following method (Points and Vectors are as you'd expect, and a Line consists of a Point on the ...
0
votes
1answer
452 views

x axis detection issues platformer starter kit

I've come across a problem with the collision detection code in the platformer starter kit for xna.It will send up the impassible flag on the x axis despite being nowhere near a wall in either ...
2
votes
2answers
873 views

Collision Resolution

Hey all, I'm making a simple side-scrolling game, and I would appreciate some input! My collision detection system is a simple bounding box detection, so it's really easy to implement. However my ...
3
votes
1answer
531 views

Creating the “game space” for a 2D game

How does one setup the game space for a game so that obstacles can be spawned? Examples would be ice climber or the iphone doodle jump. Tile maps are limited in size and would need to change often if ...
4
votes
3answers
1k views

Collision Detection in Java for a game

Im making a game in Java with a few other people but we are stuck on one part of it, making the collision detection. The game is an RPG and I know how to do the collision detection with the characters ...
9
votes
2answers
1k views

Simulating an object floating on water

I'm working on a top down fishing game. I want to implement some physics and collision detection regarding the boat moving around the lake. I would like for be able to implement thrust from either the ...
6
votes
4answers
2k views

2D Platformer Collision Handling

I am trying to create a 2D platformer (Mario-type) game and I am some having some issues with handling collisions properly. I am writing this game in C++, using SDL for input, image loading, font ...
2
votes
2answers
971 views

Projectiles in tile mapped turn-based tactics game?

I am planning to make a Laser Squad clone and I think I have most of the aspects covered. But the major headache is the projectiles shot/thrown. The easy way would be to figure out the probability of ...
1
vote
1answer
1k views

Multiple Sprites using foreach Collison Detection in XNA (C#)

Back again from my last question. Now I was curious I use a foreach statement to use the same shot class. How would I go about doing collison detection. I used the tutorial here on how to shoot a ...
1
vote
2answers
2k views

Voronoi regions of a (convex) polygon

I'm looking to add circle-polygon collisions to my Separating Axis Theorem collision detection. The metanet software tutorial (http://www.metanetsoftware.com/technique/tutorialA.html#section3) on ...
7
votes
1answer
1k views

Tile-based 2D collision detection problems

I'm trying to follow this tutorial http://www.tonypa.pri.ee/tbw/tut05.html to implement real-time collisions in a tile-based world. I find the center coordinates of my entities thanks to these ...
117
votes
9answers
23k views

How was collision detection handled in The Legend of Zelda: A Link to the Past?

I would like to know how the collision detection was done in The Legend of Zelda: A Link To The Past. The game is 16x16 tile based, so how did they do the tiles where only a quarter or half of the ...
3
votes
1answer
610 views

Breakout clone, how to handle/design for collision detection/physics between objects?

I'm working on a breakout clone, and I wish to create some realistic physics effects for collision - angles on the paddle should allow the ball to bounce, as well as doing curve balls etc. I could use ...
3
votes
3answers
1k views

Collision detection of convex shapes on voxel terrain

I have some standard convex shapes (cubes, capsules) on a voxel terrain. It is very easy to detect single vertex collisions. However, it becomes computationally expensive when many vertices are ...
8
votes
2answers
4k views

2D object-aligned bounding-box intersection test

I have two object-aligned bounding boxes (i.e. not axis aligned, they rotate with the object). I'd like to know if two object-aligned boxes overlap. (Edit: note - I'm using an axis-aligned bounding ...
14
votes
2answers
3k views

How to find if circle and concave polygon intersect?

I have a polygon (sometimes convex, but often concave), and a bunch of circles with different radius. How can I find out if a circle is intersecting/overlapping with the polygon? If it makes it ...
4
votes
4answers
1k views

Pong Collision Help in C# w/ XNA

Edit: My goal is to have it function like this: Ball hits 1st Quarter = rebounds higher (aka Y++) Ball hits 2nd Quarter = rebounds higher (using random value) Ball hits 3rd Quarter = rebounds lower ...
7
votes
5answers
1k views

How to determine which cells in a grid intersect with a given triangle?

I'm currently writing a 2D AI simulation, but I'm not completely certain how to check whether the position of an agent is within the field of view of another. Currently, my world partitioning is ...
4
votes
2answers
411 views

How to detect and collide two elastic line segments?

There are 4 moving physical nodes in 3D space. They are paired with two elastic line segments / strings (1 <-> 2; 3 <-> 4). Part I: How to detect the collision of two segments? Part II: On the ...
3
votes
1answer
836 views

problem with frustum AABB culling in DirectX

I am currently working on a project with a few friends, and I am trying to get frustum culling working. Every single tutorial or article I go to shows that my math is correct and that this should be ...
2
votes
1answer
257 views

Collision filtering by object, team

I am looking for a good method to determine which objects will be considered for collision with other objects. My current idea is that each object has the following properties: alwaysCollidesWith = ...
1
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3answers
2k views

How to detect which edges of a rectange touch when they collide in iOS

I'm creating a basic "game" in iOS 4.1. The premise is simple, there is a green rectangle ("disk") that moves/bounces around the screen, and red rectangle ("bump") that is stationary. The user can ...
5
votes
1answer
804 views

How to calculate new direction after sprite collision

The scenario as you can see in the picture. A ball will be hitting a surface and I want to fairly correctly get the new angle after the collision.. I expect to know the X,Y coordinates of the lines ...
4
votes
3answers
1k views

Point line collision reaction

I am trying to program point line segment collision detection and reaction. I am doing this for fun and to learn. The point moves (it has a velocity, and can be controlled by the user), whilst the ...
4
votes
4answers
5k views

How to find out if two circles intersect each other

I want to find the intersecting of 2 circles with radius r1 and r2 (simple solutions preferred).
7
votes
2answers
636 views

Collision Systems Implementation

Just curious what might be a good way to implement a decent collision system. As a class inherited by a base Entity class? Currently I'm stuck and could just use a couple better ideas than my own. ...
5
votes
3answers
568 views

What causes player box/world geometry glitches in old games?

I'm looking to understand and find the terminology for what causes - or allows - players to interfere with geometry in old games. Famously, ID's Quake3 gave birth to a whole community of people ...
1
vote
3answers
2k views

Collision Detection for 2D

I am working on a simple game, where I need to do a collision detection of two Texture2D. The code I have written is: bool perPixelCollission = false; Texture2D texture1 = ...
2
votes
3answers
2k views

Easiest way to compute closest point between two triangular meshes

What is the easiest (not most efficient or fastest) algorithm to find the closest points between two triangular meshes? What are the easiest early out algorithms in the broad phase? What kind of broad ...
2
votes
1answer
1k views

BoundingFrustum Performance Issues

I have noticed that BoundingFrustum.Intersects() is a rather slow check in XNA. I am doing only 256 checks per frame and it eats up arround 50-60% of availible time when running at 60fps. This is kind ...
14
votes
1answer
7k views

Quad tree vs Grid based collision detection

I'm making a 4 player co-op r-type game, and I'm about to implement the collision detection code. I've read a lot of articles and stuff about how to handle collision detection, but I'm having a hard ...
4
votes
1answer
2k views

Farseer and 2D Action sidescroller game

I'm thinking about using Farseer inside my game (I'm not good in physics), which isn't a bad idea. However something happened while I was thinking about that, I found this tutorial: ...
6
votes
3answers
6k views

2D Side Scrolling game and “walk over ground” collision detection

The question is not hard, I'm writing a game engine for 2D side scrolling games, however I'm thinking to my 2D side scrolling game and I always come up with the problem of "how should I do collision ...
3
votes
1answer
262 views

Name of the model in memory that you use for map collision detection?

I'm trying to remember the English name for a memory model of a map built exclusively for handling collision detection. I think this is especially frequent in tile-based platform games. I believe the ...
14
votes
5answers
5k views

Collision Resolution

I know quite well how to check for collisions, but I don't know how to handle the collision in a good way. Simplified, if two objects collide I use some calculations to change the velocity direction. ...
7
votes
4answers
1k views

Implementing 2D CSG (for collision shapes)?

Are there any simple (or well documented) algorithms for basic CSG operations on 2D polygons? I'm looking for a way to 'add' a number of overlapping 2D collision shapes. These may be convex or ...
6
votes
2answers
2k views

How can I implement rectangle collision response?

I am working on a game in JavaScript and my current implementation of collision uses the shortest distance to push the intersecting object away, which isn't always correct. I've made this diagram of ...